1. The Field of the Invention
The present invention relates to an apparatus and system for use in RNA interference. More particularly, the present invention relates to an apparatus and system that includes well plates having dry gene silencing compositions comprised of siRNA.
2. The Related Technology
Recently, a natural cellular regulatory pathway was discovered that uses transcribed microRNA (“miRNA”) in order to control protein production. The miRNA includes a duplex region of sense and antisense RNA. This regulatory pathway uses miRNA in order to target complementary mRNA to inhibit production of the encoded protein. Accordingly, a complex series of proteins are involved in this RNA interfering pathway to inhibit or stop production of the proteins encoded by the mRNA. As such, the process is referred to as RNA interference or RNAi.
Additionally, it has been found that the RNAi pathway can be used with synthetic dsRNA (e.g., siRNA) for silencing genes and inhibiting protein expression. This can allow for siRNA having specific sequences to be produced to target complementary DNA and/or mRNA encoding a specific protein. The siRNA can interact with the natural RNAi pathway to silence a target gene and inhibit production of the encoded polypeptide. The ability to silence a specific gene and inhibit production of the encoded protein has been used for basic research of gene function, gene mapping, cellular pathway analysis, and other gene-related studies.
In order to induce gene silencing, the siRNA needs to be introduced into a cell. While the most common procedures for introducing nucleic acids into cells has been forward transfection, reverse transfection (“RTF”) has been developed more recently and used as an alternative to forward transfection procedures. In certain versions of RTF protocols, a complex of lipid-nucleic acid (e.g., lipoplex) can be prepared and introduced into the test wells of a well plate. Cells are introduced into the test wells with the lipid-nucleic acid complexes, and incubated so that the siRNA can enter the cells. Examples of some RTF protocols can be found in U.S. Pat. No. 5,811,274 to Palsson, U.S. Pat. No. 5,804,431 to Palsson and U.S. Pat. No. 6,544,790 to Sabatini and in U.S. Published Applications 2002/0006664 to Sabatini and 2003/070642 to Caldwell et al. As described in these references, RTF procedures for nucleic acids generally can have fewer steps compared to traditional forward transfection and may offer benefits in attempting to isolate the transfected cells to particular regions of a single surface, such as a glass slide. However, RTF procedures for siRNA have not been optimized to the point of practical application, and improvements in gene silencing efficacy are still needed, especially for situations in which one is experimenting with multiple different siRNAs, different gene targets or different cell lines.
Therefore, it would be advantageous to have an improved RTF protocol for delivering siRNA into cells to effect gene silencing through the RNAi pathway. Additionally, it would be beneficial to have the RTF format, including the siRNA, configured in a manner that enhances the efficacy of gene silencing.